Site Mobile Navigation

Eating Well; More to Cooking Burgers Than Meets the Eye

SO you think your hamburger is safely cooked when it is brown all the way through? Forget it.

Hamburger meat turns brown for reasons that have nothing to do with cooking, according to tests done by the Federal Government. And that means it can hold bacteria that make you sick.

Researchers at the Agriculture Department spent eight months testing meat that had browned prematurely, that is, browned simply because it had been exposed to air and light. They discovered that premature browning occurs ''at such a significant rate that color can no longer be considered a good indicator that hamburger has been cooked to 160 degrees,'' the temperature at which all harmful bacteria are destroyed.

The department bought 240 pairs of packages of ground beef from stores around the country. Some of the patties made from them were frozen and then cooked, and some were cooked without freezing.

The patties were cooked to one of four temperatures: 135 degrees, 150 degrees (both too low to assure safety), 160 degrees (the department's recommended cooking temperature) and 175 degrees, at which a hamburger has lost most of its juices. The color of these hamburgers was rated on a scale of 1 (reddest) to 5 (brownest). A 3.5 rating indicated slight pink, while 4 indicated no pink.

Variations in color occurred even in patties that were cooked at the same temperature. While most of the patties that were cooked to 135 and 150 degrees looked on the rare side, as might be expected, some reached the 3.5 level of slight pinkness. More than 47 percent of the patties cooked to 160 degrees were slightly pink, while 23 percent were scored at 4, showing no pinkness.

The researchers found that freezing ground beef and thawing it overnight in the refrigerator greatly increased its chances of turning brown before it was thoroughly cooked. But whether the meat was frozen or not, the color could range from brown to bright pink before cooking.